title: A spontaneous Cdt1 mutation in 129 mouse strains reveals a regulatory domain restraining replication licensing.
abstract: Cdt1 is required for loading the replicative DNA helicase MCM2/7, a process known as DNA replication licensing. Here we show that 129 mouse strains express a Cdt1 mutated allele with enhanced licensing activity. The mutation, named Δ(6)PEST, involves a six-amino acid deletion within a previously uncharacterized PEST-like domain. Cdt1 Δ(6)PEST and more extensive deletions exhibit increased re-replication and transformation activities that are independent of the Geminin and E3 ligase pathways. This PEST domain negatively regulates cell cycle-dependent chromatin recruitment of Cdt1 in G2/M phases of the cell cycle. Mass spectrometry analysis indicates that Cdt1 is phosphorylated at sites within the deleted PEST domain during mitosis. This study reveals a conserved new regulatory Cdt1 domain crucial for proper DNA licensing activity and suggests a mechanism by which the presence of Cdt1 in G2/M phases does not lead to premature origin licensing. These results also question the usage of 129 mouse strains for knockout analyses.
authors.affiliation: Replication and Genome Dynamics Group, Institute of Human Genetics, CNRS, 141 rue de la Cardonille, 34396 Montpellier, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Coulombe
authors.forename: Damien
authors.initials: D
authors.lastname: Grégoire
authors.forename: Nikolay
authors.initials: N
authors.lastname: Tsanov
authors.forename: Marcel
authors.initials: M
authors.lastname: Méchali
mesh_terms: D000483:Alleles; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D063646:Carcinogenesis; D018797:Cell Cycle Proteins / Q000737:chemistry* / Q000235:genetics*; D002457:Cell Extracts; D002460:Cell Line; D002843:Chromatin / Q000378:metabolism; D004261:DNA Replication; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000235:genetics*; D064248:Geminin / Q000378:metabolism; D006801:Humans; D051379:Mice; D057507:Mice, 129 Strain; D008938:Mitosis; D008954:Models, Biological; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics*; D041681:NIH 3T3 Cells; D010766:Phosphorylation; D017434:Protein Structure, Tertiary; D017384:Sequence Deletion; D044767:Ubiquitin-Protein Ligases / Q000378:metabolism
chemical_list: D018797:Cell Cycle Proteins; D002457:Cell Extracts; D002843:Chromatin; D004268:DNA-Binding Proteins; D064248:Geminin; C498645:Ris2 protein, mouse; D044767:Ubiquitin-Protein Ligases